Indium Complexes of Fluorinated Dialkoxy-Diimino Salen-like Ligands for Ring-Opening Polymerization of rac-Lactide: How Does Indium Compare to Aluminum?
Indium Complexes of Fluorinated Dialkoxy-Diimino Salen-like Ligands for Ring-Opening Polymerization of rac-Lactide: How Does Indium Compare to Aluminum?
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DOI：
10.1021/om200906e
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发表时间：
2012-02-27
期刊：
影响因子：
2.8
通讯作者：
Carpentier, Jean-Francois
中科院分区：
文献类型：
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作者：
Normand, Mickael;Kirillov, Evgeny;Carpentier, Jean-Francois
（CF3）(2)(OH)CCH2C(CH3)=N-R-N=C(CH3)-CH2C(OH)(CF3)(2) ({（ONNO)-N-Et}H-2, R = C2H4 (a)）与{(ONNO)-N-Et}K-2的反应（1a）；{（ONNO)-N-Cy}H-2, R = rac-1,2-环己烯(b)）和PhCH2K，得到{(ONNO)-N-Et}InCl （2a）。cl3与3等分MeLi反应生成[InMe3]和Li[InMe4]的混合物，再用{(ONNO)-N-R}H-2前配体处理得到[{(ONNO)-N-R}Li]InMe2 (4a,b)；甲基络合物{(ONNO)-N-Et}InMe （3a）也从该反应中分离得到。以In(CH2SiMe3)(3)和{ONRNO}H-2为原料，以1:1的比例反应制备了{(ONNO)-N-R}In(CH2SiMe3) （5a,b）。测定了单核2a、3a、4b和5b的固态分子结构，以及（1a）(2)中心点（mu-H2O）](n)，一个由4个钾原子和2个配体组成的扭曲的c-uban状核。化合物5a、b是racc -丙交酯开环聚合的中等活性引发剂/催化剂，产生分子量可控、多分散性窄的聚合物，特别是在添加异丙醇（1-10当量）作为外源引发剂的情况下。5a为等规富集（P-m = 0.62-0.69） pla， 5b为无规物质。杂双金属化合物4a和b也具有活性，并提供了微杂性富集的pla (P-r = 0.57-0.62)，但具有更广泛的多分散性。这些结果使我们能够根据体系的构成（烷基vs烷基/iPrOH）以及作为金属中心性质（In vs Al）和配位环境(kappa（4)-ONNO vs kappa(2)-NN）的函数的立体选择能力来讨论引发机制。
The reaction between InCl3 and {(ONNO)-N-Et}K-2 (1a), prepared from (CF3)(2)(OH)CCH2C(CH3)=N-R-N=C(CH3)-CH2C(OH)(CF3)(2) ({(ONNO)-N-Et}H-2, R = C2H4 (a); {(ONNO)-N-Cy}H-2, R = rac-1,2-cyclohexylene (b)) and PhCH2K, gave {(ONNO)-N-Et}InCl (2a). The reaction between InCl3 and 3 equiv of MeLi led to a mixture of [InMe3] and Li[InMe4] which upon further treatment with {(ONNO)-N-R}H-2 proligands gave the ate complexes [{(ONNO)-N-R}Li]InMe2 (4a,b); the methyl complex {(ONNO)-N-Et}InMe (3a) was also isolated from this reaction. Hydrocarbyl complexes {(ONNO)-N-R}In(CH2SiMe3) (5a,b) were prepared cleanly from the 1:1 reactions between In(CH2SiMe3)(3) and {ONRNO}H-2. The solid-state molecular structures of mononuclear 2a, 3a, 4b, and 5b and of ((1a)(2)center dot(mu-H2O)](n), a distorted c-ubane-like core made up of four potassium atoms and two ligands, were determined. Compounds 5a,b are moderately active initiators/catalysts for the ring-opening polymerization of rac-lactide, giving polymers with controlled molecular weights and narrow polydispersities, especially in the presence of added isopropyl alcohol (1-10 equiv) as exogenous initiator. Isotactic-enriched (P-m = 0.62-0.69) PLAs were obtained from 5a, while 5b gave atactic materials. The heterobimetallic compounds 4a,b are also active and afforded slightly heterotactic-enriched PLAs (P-r = 0.57-0.62), but with broader polydispersities. Those results allowed us to discuss the initiation mechanisms according to the constitution of the systems (alkyl vs alkyl/iPrOH) and also stereoselective abilities as a function of the nature (In vs Al) and coordination environment (kappa(4)-ONNO vs. kappa(2)-NN) of the metal center.